Barrel query

[Hillhunter]

Looking at changing my 1/10 twist barrel to shoot the Berger 215 Hybrids , I have shot them quiet successfully for the past 6 months but when I put the info into the twist rate calculator it tells me I am marginally stable , my question is do I go for a 1/9 ? Or what do I order , also what length barrrel would be optimal for the 215's . I was told by a fellow shooter that a 1/8.5, 6 groove would be the preferred option but I don't think this has been tested.

 

[Dgd6mm]

Hopefully DownSouth, Savageshooter86, or Steve Blair will reply on your thread. They have been shooting them pretty successfully. Have you done a search? There may be some good info in the archives.

 

[Hillhunter]

Hopefully DownSouth, Savageshooter86, or Steve Blair will reply on your thread. They have been shooting them pretty successfully. Have you done a search? There may be some good info in the archives.

yes I have tried the search but cannot find answers to my query, thanks

 

[Marksman63]

I found out a previuos post.

Here is one of Bryan Litz's replies:

Alex,

Interesting question. As head coach of the Michigan FTR team, I've got a lot of insight to share on that subject, since most of our team (~15 shooters) have been shooting 215 Hybrids for the past 3 years from 9 and 10 twist 308 Win barrels.

In the previous 2 years, we shot 1:9" twist barrels, because there is a small but measurable improvement in BC for the 9 twist compared to the 1:10".

Although the 1:9"s have shot many 197's, 198's, and 199's, the only 200's shot by our team at 1000 yards (that I'm aware of) have been with 1:10" twist barrels.

Apparently, the slight edge in BC for the 1:9" twist is not outweighed by the inherent precision of the slower twist, even at 1000 yards.

I'm sure a 1:9.5" would work, but it's splitting hairs since we see such a small difference between 1:9" and 1:10".

Of course if your shooting the 215 Hybrids out of a larger case at higher speeds, the 1:10" may provide full stability and BC.

-Bryan
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[Hillhunter]

I found out a previuos post.

Here is one of Bryan Litz's replies:

Alex,

Interesting question. As head coach of the Michigan FTR team, I've got a lot of insight to share on that subject, since most of our team (~15 shooters) have been shooting 215 Hybrids for the past 3 years from 9 and 10 twist 308 Win barrels.

In the previous 2 years, we shot 1:9" twist barrels, because there is a small but measurable improvement in BC for the 9 twist compared to the 1:10".

Although the 1:9"s have shot many 197's, 198's, and 199's, the only 200's shot by our team at 1000 yards (that I'm aware of) have been with 1:10" twist barrels.

Apparently, the slight edge in BC for the 1:9" twist is not outweighed by the inherent precision of the slower twist, even at 1000 yards.

I'm sure a 1:9.5" would work, but it's splitting hairs since we see such a small difference between 1:9" and 1:10".

Of course if your shooting the 215 Hybrids out of a larger case at higher speeds, the 1:10" may provide full stability and BC.

-Bryan
Report to moderator Logged

Thanks marksman63 I have seen that post , it's just that I have been told that some have tried 1/8.5 twist and shorter barrel length with good results but I cannot get anyone to verify it.by the way I'm using a 32 inch barrel., maybe shorter would be better

 

[geraldgee]

Per your post, you have been shooting them "quite successfully" for the past 6 months. Seeing is believing and the proof is on the target. I wouldn't change anything if they are shooting well.

Good luck,
Gerald

 

[Hillhunter]

Per your post, you have been shooting them "quite successfully" for the past 6 months. Seeing is believing and the proof is on the target. I wouldn't change anything if they are shooting well.

Good luck,
Gerald

Thanks Gerald , yes I said quiet successfully but I thought I might do better with a different twist and barrel length, hopefully someone who shoots the 215's in a different set up might reply to the thread
HH

 

[paulT]

I found out a previuos post.

Here is one of Bryan Litz's replies:

Alex,

Interesting question. As head coach of the Michigan FTR team, I've got a lot of insight to share on that subject, since most of our team (~15 shooters) have been shooting 215 Hybrids for the past 3 years from 9 and 10 twist 308 Win barrels.

In the previous 2 years, we shot 1:9" twist barrels, because there is a small but measurable improvement in BC for the 9 twist compared to the 1:10".

Although the 1:9"s have shot many 197's, 198's, and 199's, the only 200's shot by our team at 1000 yards (that I'm aware of) have been with 1:10" twist barrels.

Apparently, the slight edge in BC for the 1:9" twist is not outweighed by the inherent precision of the slower twist, even at 1000 yards.

I'm sure a 1:9.5" would work, but it's splitting hairs since we see such a small difference between 1:9" and 1:10".

Of course if your shooting the 215 Hybrids out of a larger case at higher speeds, the 1:10" may provide full stability and BC.

-Bryan
Report to moderator Logged

what was elevation of range used to test the 1 in 9 and 1 in 10 twist barrels with the 215H, Thinking a 1 in 9 or faster would be needed if elevations closer to sea level as is the case with most ranges in ireland and uk.

 

[calgarycanada]

I recommend you stick with 10 twist unless you are planning to shoot at sea level most of the time.
When it comes to experience I'm probably the last in line here but this is my experience
A very experienced guy recommend 9 twist to me to get all the BC out of 215s and I ordered Benchmark MTU 30" 1-9.
A master machinist and gunsmith chambered it(and double checked it afterwards)
I have tried quite a few powders and 3 different type of bullets including 215s and 208s. It would not shoot, not even consistent 1/2 moa. I finally figured it out that it shoots at slower velocities only. Even at those velocities it likes to throw elevation shots here and there. The pressure in all half decent loads is so low that I get soot on half the case shoulders(brass annealed every other firing) and velocities must be kept slower then my factory 24" barrel. (That was my little sob story)
I have been in contact with the dealer I ordered it from and he's blaming it all on twist rate that "I" picked so I'm SOL. You be the judge & of course YMMV

 

[paulT]

I recommend you stick with 10 twist unless you are planning to shoot at sea level most of the time.
When it comes to experience I'm probably the last in line here but this is my experience
A very experienced guy recommend 9 twist to me to get all the BC out of 215s and I ordered Benchmark MTU 30" 1-9.
A master machinist and gunsmith chambered it(and double checked it afterwards)
I have tried quite a few powders and 3 different type of bullets including 215s and 208s. It would not shoot, not even consistent 1/2 moa. I finally figured it out that it shoots at slower velocities only. Even at those velocities it likes to throw elevation shots here and there. The pressure in all half decent loads is so low that I get soot on half the case shoulders(brass annealed every other firing) and velocities must be kept slower then my factory 24" barrel. (That was my little sob story)
I have been in contact with the dealer I ordered it from and he's blaming it all on twist rate that "I" picked so I'm SOL. You be the judge & of course YMMV

Hi Calgarycanada, Would you mind sharing more info e.g elevation used for your shooting the 215H, Number of groves in barrel and velocity you were running those 215H, I found excellent accuracy at @ 2,680 and 2,720fps using varget however large percentage of Lapua BR brass was toast with high pressures with loads using varget, also tried re-17 which is much easier on brass.

 

[calgarycanada]

3500 ft
3 groove
I have tried shooting from 2495 fps to 2640 fps. Any higher I was getting pressure signs and lapua brass is expensive you know
For powders I have tried H4350, Varget, H 4895, RL 17

 

[paulT]

I found H4895 and varget accurate however to hard on brass with 200g to 215g Hybrids, H4350 will get lower node 2,620 fps with compressed charges, would be great if hodgdons would produce a stick powder in their extreme range between Varget and H4350 burn rate which would be ideally suited for 215g hybrid in .308.

 

[kyreloader]

I found H4895 and varget accurate however to hard on brass with 200g to 215g Hybrids, H4350 will get lower node 2,620 fps with compressed charges, would be great if hodgdons would produce a stick powder in their extreme range between Varget and H4350 burn rate which would be ideally suited for 215g hybrid in .308.

IMR 4451 might just be perfect. Seems to have burn rate right where are you looking for it to be.

 

[Canadian bushman]

Ive been shooting the 215 in a 308 outta a 1:10.5 for just over two years now.

My next barrel will be a 1:9.5

For targets and group shooting the 1:10 is fine but variations in bc due to velocity and atmospherics are getting old. I think my first round accuracy will benifit from a tighter twist. It has in other rifles anyways.

 

[paulT]

I found H4895 and varget accurate however to hard on brass with 200g to 215g Hybrids, H4350 will get lower node 2,620 fps with compressed charges, would be great if hodgdons would produce a stick powder in their extreme range between Varget and H4350 burn rate which would be ideally suited for 215g hybrid in .308.

IMR 4451 might just be perfect. Seems to have burn rate right where are you looking for it to be.

Thanks for info Kyreloader, will have to try out IMR 4451, is it temp stable like hodgdon extreme line of powders.

 

[paulT]

Ive been shooting the 215 in a 308 outta a 1:10.5 for just over two years now.

My next barrel will be a 1:9.5

For targets and group shooting the 1:10 is fine but variations in bc due to velocity and atmospherics are getting old. I think my first round accuracy will benifit from a tighter twist. It has in other rifles anyways.

Hi Canadian bushman, thanks for sharing info with barrel twist for 215h, wonder would a 6 groove 28-30 inch heavy profile barrel with 1 in 9 twist be optimum for low elevation shooting e.g 200-800ft above sea level for the 215g hybrids also thinking a lighter diameter bore over a tight bore might deform the 215h less for long range accuracy.

 

[tika]

looking at the twist rate calculator it shows the 1/9 is more stable than a 1/9.5

 

[Canadian bushman]

Ive been shooting the 215 in a 308 outta a 1:10.5 for just over two years now.

My next barrel will be a 1:9.5

For targets and group shooting the 1:10 is fine but variations in bc due to velocity and atmospherics are getting old. I think my first round accuracy will benifit from a tighter twist. It has in other rifles anyways.

Hi Canadian bushman, thanks for sharing info with barrel twist for 215h, wonder would a 6 groove 28-30 inch heavy profile barrel with 1 in 9 twist be optimum for low elevation shooting e.g 200-800ft above sea level for the 215g hybrids also thinking a lighter diameter bore over a tight bore might deform the 215h less for long range accuracy.

I live in south tx @ 60ft asl. I also have a fast barrel shooting mid 2600's. So in the winter time where our temps will hit maybe 30 for a couple days, maybe weeks a 1:9.5 will push me towards the edge of optimal stability probably shaving a little off the bc. A 1:9 probably will not experience this issue, its pretty dependant to be able to say to what degree. For the other 90% of the year it will work really well. I do most of my shooting in the spring and fall so anywhere between 1:9-1:10 would probably work just fine for me. Your enviroment may differ.

The last few lots of 215's i mic-ed ran almost just at .308-.3082 so i personally would look to a nominal .300-.308 bore.

I run a 3grv, 30" , lilja #7. My next barrel will probably be heavier. The gun weighs 16.5 now and recoil is a bit much for me in a match. Just a few shots is tolerable.

 

[Canadian bushman]

looking at the twist rate calculator it shows the 1/9 is more stable than a 1/9.5

Wouldnt doubt that for a second.

 

[paulT]

I along with couple of shooters on Irish team shot few hundred 215h over couple of days at last creedmore shoot in Ireland along with another match sure knew we shot them, They are very sensitive to grip and cheek weld and consistency is the name of the game with the 215h if verticals to be kept to minimum however they are a mighty bullet in v rough conditions.